A Novel Broadband Notch-Band Vivaldi Antenna with Enhanced Out-of-Band Suppression

The paper presents a novel broadband notch-band antenna featuring enhanced out-of-band suppression performance. The antenna is fabricated on a Rogers 4350B substrate with a dielectric constant of 3.66, a thickness of 1.524mm, and a loss tangent of 0.004. With overall dimensions of 234.6 mm×207 mm×1.524 mm, the design employs dual 50-g SMA connectors for differential feeding. The antenna architecture integrates a modified Vivaldi structure with strategically designed filter slots and half-wavelength open-circuit stubs, achieving dual operational bands of 1.14-2.49 GHz and 3.41-5.00 GHz. A distinctive band-notched characteristic spanning 2.53-3.35 GHz has been implemented to effectively suppress interference, such as that from the N41 band (2.496-2.69 GHz) and S-band satellite communications (2.7-3.35 GHz). The antenna demonstrates high directivity along the end-fire direction. It maintains stable radiation efficiency across the 1.14-4.95 GHz frequency range, exhibiting [Sdd11] values below −10 dB except within the 2.69-3.45 GHz suppression band. Notable features include superior cross-polarization suppression, filtering performance integration, making this design suitable for advanced radio frequency front-end applications.